Jessica L. Barrington-Trimis, Ph.D., from the Keck School of Medicine at the University of Southern California in Los Angeles, and colleagues collected data via an online survey from 1,312 participants in the Southern California Children’s Health Study at baseline (2015 to 2016) and follow-up (2016 to 2017). The association between three characteristics of the e-cigarette used most frequently with the number of cigarettes smoked in the past 30 days at follow-up was assessed.

The researchers observed an association between past 30-day e-cigarette use and greater frequency of past 30-day cigarette smoking at follow-up, relative to never e-cigarette use. After adjustment for sociodemographic characteristics, baseline frequency of cigarette smoking, and number of days of e-cigarette use, among baseline past 30-day e-cigarette users, those who used mods versus vape pens smoked more than six times as many cigarettes at follow-up (mean, 20.8 versus 1.3 cigarettes; rate ratio, 6.33). Neither nicotine e-liquid nor dripping were associated with the frequency of cigarette smoking after adjustment for device.

“Additional research is needed to explore causal pathways for the observed associations,” the authors write. “If these associations were causal, device type and characteristics may be a target for regulation to reduce the burden of tobacco-related disease that may result from adolescent and young adult vaping.”